The present invention relates to an apparatus for trapping and killing insects and/or small animals (which are inclusively referred to as the xe2x80x9cinsect or the likexe2x80x9d or xe2x80x9cInsectxe2x80x9d hereinafter). The apparatus is referred to as the xe2x80x9cinsect-trapping/killing apparatusxe2x80x9d hereinafter.
An outbreak of a large number of Insects harmful to agricultural products causes significant damages to the products. In order to prevent such damages, various countermeasures, such as sprinkling a large amount of agricultural chemical insecticides, are conventionally taken. In addition, various surveys are conducted to detect an outbreak of harmful insects in its early phase or to confirm the effect of countermeasures taken against the harmful insects.
In a survey for grasping the state of an outbreak of Insects or the process of their eradication, an apparatus called a xe2x80x9cpheromone trapxe2x80x9d is often used, which attracts and traps the Insects using a pheromone or other attractant for attracting particular kinds of Insects. The pheromone trap is placed on the survey site for a preset time period, and the number of Insects trapped thereby is checked at regular intervals to confirm the state of outbreak of the Insects or the effect of the countermeasures taken against it. This method, however, has a problem in that a large amount of time and labor is consumed to count the number of Insects trapped by the pheromone traps. Further, it is generally necessary to count the number of the trapped creatures every twenty-four hours. Thus, according to the conventional practice, the trapped Insects are manually collected every twenty-four hours, which also consumes a large amount of time and labor.
Taking account of the above problems, the applicant proposed an apparatus for automatically attracting, trapping, killing and counting Insects, as disclosed in Japanese Unexamined Patent Publication No. 2000-50. The apparatus is constructed so that a particular kind of Insect attracted by an attracting means, such as pheromone, is guided into a space between a pair of electrodes to which a high voltage is applied, and an electric discharge that passes through the Insect when the creature arrives at the space between the electrodes is counted to obtain the number of the trapped creatures. Here, if the Insect that has already been counted is not completely trapped and is allowed to escape, it is possible for the same creature to be counted again, which devalues the counting accuracy. In order to prevent this, the above-described apparatus is constructed to apply a high voltage to the electrodes so that the counted Insect is completely trapped and killed.
In the above apparatus, however, various problems arise when the distance between the electrodes and the voltage applied to the electrodes are not appropriately determined. For example, when the voltage is too high, the dead body of the Insect killed by the electric discharge easily adheres to the electrode due to static electricity. Another problem is that a higher voltage makes it more difficult to prepare the power source (for example, when the solar cell is not available). Still another problem is that a higher voltage is naturally dangerous to the human body, too. When, on the other hand, the voltage is too low, the killing capability is inadequate, so that the above-described problem of multiple-count of the same Insect arises. When the distance between the electrodes is reduced, electric discharge of an adequate energy may be generated even at a low voltage. This, however, causes another problem that a large Insect may clog the space between the electrodes.
When the Insect to be trapped and killed has wings, for example a moth, the above problem is particularly remarkable. That is, the electric resistance of a wing of an Insect is greater than that of the body, so that the electric current is sometimes inadequate to kill the insect if the electric discharge first passes through the wing. One of the methods of preventing this situation is to reduce the distance between the electrodes to ensure the electric discharge to occur through the body of the Insect. Another is to adequately increase the voltage between the electrodes so that the Insect is killed even through the wings. By the former method, however, an Insect with its wings spread may clog the space between the electrodes, and by the latter method, the electrostatic adhesion may occur.
In view of the above problems, in an insect-trapping/killing apparatus including:
at least a pair of electrodes for generating an electric discharge;
a voltage-applying means for applying a preset voltage between the electrodes; and
a removing mechanism for moving at least one of the pair of the electrodes to remove an insect or the like from the space between the electrodes, the insect-trapping/killing apparatus according to the invention is characterized in that:
the apparatus further includes a pair of roller electrodes disposed parallel to each other as said pair of the electrodes, and an electrode-driving mechanism for rotating each roller electrode on a central axis thereof; and
the insect or the like existing in the space between the electrodes is removed from the space between the electrodes when the electrode-rotating mechanism rotates the pair of the roller electrodes in opposite directions.
The second insect-trapping/killing apparatus according to the present invention is characterized by including a pair of rollers disposed parallel to each other with the distance preset according to the size of an insect or the like to be killed; a guiding means for guiding the insect or the like into the space between the pair of rollers; and a roller-driving mechanism for rotating each roller on a central axis thereof, wherein
the insect or the like is pulled into the space between the pair of rollers and squashed thereby when the roller-driving mechanism rotates the pair of rollers in opposite directions.
In the first insect-trapping/killing apparatus, at least one electrode is constructed as movable, and when the electrode is moved with a motor or other driving device, the Insect existing between the electrodes is removed from there. The manner of removing the Insect from the space between the electrodes by moving the electrode is appropriately determined by taking account of the arrangement and/or shape of the electrodes. For example, in the present invention, the pair of electrodes is a pair of cylindrical electrodes disposed parallel to each other, and one or both of the electrodes are rotated on the central axis of the cylinder to remove the Insect existing between the electrodes by the frictional force. When the pair of electrodes is a pair of plate electrodes disposed parallel to each other, one possible method is to move one electrode parallel to the other to remove the Insect existing between the electrodes by the frictional force. Another possible method is to temporarily increase the distance between the electrodes to let fall the Insect existing between the electrodes due to the gravitational force. With the removing mechanism as described above, the Insect can certainly be removed even when the distance between the electrodes is set as small as the size of the body of the Insect, where the size is measured excluding wings and other soft parts, so that the problem of the clogging the space between electrodes by the Insect never arises.
Thus, in the first insect-trapping/killing apparatus, the distance between the electrodes can be reduced without concerning the problem of the clogging of the space between the electrodes by the Insect, which enables the generation of a strong electric discharge even at a relatively low voltage. The reduction of the distance between the electrodes ensures the contact between the body of the Insect and the electrode, so that the Insect can be more certainly killed. The lowering of the voltage also provides other effects such that the problem of the electrostatic adhesion hardly arises and that it is less dangerous to the user. Further, when there is no need to generate a high voltage, the power supply system can be simplified, so that the cost is reduced.
The first insect-trapping/killing apparatus may be further provided with a discharge detection means for counting the occurrence of electric discharges between the electrodes, which makes an apparatus for counting and killing insects that automatically traps, kills and counts Insects. Since, in the apparatus for counting and killing insects constructed using the first insect-trapping/killing apparatus, the Insects are almost certainly killed, the problem of the multiple-count of the same Insect never arises, so that high counting accuracy is obtained. The above insect-trapping/killing apparatus, or the apparatus for counting and killing insects, may be further provided with attracting means for attracting a particular kind of Insect, using attractants, for example, to make an automatic apparatus for trapping, killing and/or counting only a particular kind of Insect.
The second insect-trapping/killing apparatus is constructed so that an Insect is guided into the space between a pair of rollers disposed parallel to each other with a distance slightly smaller than the size of the Insect, and when the rollers are rotated in the opposite directions, the Insect is squashed by the rollers on both sides; thus destroying the Insect physically. The second insect-trapping/killing apparatus requires no electrode for killing the Insect by electric discharge, so that the above-described problems never occur. The electrical system can be as simple as driving the motor alone for rotating the rollers, which can be constructed at low cost. Since there is no need to generate a high voltage, it is less dangerous to the user.
The second insect-trapping/killing apparatus may further include detection means for detecting the arrival of an Insect, and the roller-driving mechanism rotates the rollers when the Insect is detected with the detection means. This construction preferably reduces the consumption of electricity. For example, the detection means is constructed to detect an electric discharge generated when an Insect enters the space between a pair of electrode disposed at a preset position in a guiding passage, or to detect the arrival of an Insect based on the output signal of a photosensor or sound sensor disposed at a preset position in a guiding passage. The detection means may also be used to count the number of the Insects.